Some azole derivatives have been provided as herbicides. For example, Japanese Patent Laid Open Publication No. 147267/1980 discloses azolyloxy-carboxylic acid amides of the formula: ##STR2## and their use as herbicides. EP-A-18497 discloses compounds having substituted acetic acid anilide structure of the formula: ##STR3## and their use as herbicides. EP-A-94541 discloses substituted 5-trifluoromethyl-1,3,4-thiadiazole-2-yl-oxy-acetic acid amides of the formula: ##STR4## and their use as herbicides. However, no literature has disclosed 3-perfluoroalkyl-5-substituted-oxy-isoxaozle derivatives.
It has been found that the 3-perfluoroalkyl-5-substituted-oxy-isoxaozle derivatives show a high selectivity, specifically on pre-emergence application, and herbicidal activity without producing any material phytotoxicity on various agricultural crops such as rice, wheat, soybean, cotton and the like.